Applicants claim priority under 35 U.S.C. xc2xa7119 of German Application No. 199 26 567.4 filed Jun. 11, 1999. Applicants also claim priority under 35 U.S.C. xc2xa7120 of PCT/DE00/01456 filed May 5, 2000. The international application under PCT article 21 (2) was not published in English.
The invention relates to a cooled piston for internal combustion engines with the features according to the introductory part of claim 1.
Such pistons are known from DD 252 638 A1 and DE 41 34 530 A1. In said pistons, the part of the wall serving for covering the downwardly open cooling channel extending all around in the form of a ring is realized in the form of an open sheet metal ring. Using the elastic deformation of said ring according to the Seeger ring principle, i.e. with initial tension in the radial direction, said sheet metal ring is disposed in a groove provided on the inner periphery of the piston ring zone, and the outer periphery of the wall of the combustion chamber.
A piston crown component is known from DE 42 08 037 C2, in connection with which the cooling channel, which is open at the bottom, is covered by a radially fixed, tensioned cup spring that is split at least two times along its periphery, and freely rests on supports radially located on the inside and outside on axially opposed sides.
A piston with a cooling channel in the piston crown is known from DE 39 91 677 T1 in connection with which provision is made for a baffle plate covering the lower open end of the cooling channel. The ends of said baffle are vertically bent off upwards in the zone of the split in order to maintain the cooling oil in the cooling channel at a defined level.
The above embodiments have the drawback that the feed of cooling oil to the cooling channel is not satisfactorily solved to the desired extent.
Therefore, the invention is based on the problem of improving the feed of the cooling oil in order to obtain a favorable degree of entrapment or filling of oil in the cooling channel.
Said problem is solved in a piston of the type specified above by the features according to the characterizing part of patent claim 1.
Other useful variations according to the invention are contained in the dependent claims.